Mercury vapor anode



Filed Aug. 3l, 1931 I INVENTOR Maz Wl/ader A ORNEY Patented Mar. 21,1933 UNITED STATES PATENT OFFICE MAX WELLAUER, 0F OERLIKON, NEAR ZURICH,SWITZERLAND, i' ASSIGNOR TO SWITZERLAND MERCURY VAPOR AN ODE Applicationfiled August 31, 1931, Serial No.

This invention relates to anodes for mercury vapor rectiliers. In anodesfor rectiiiers of high current intensity it is important to transfer theenergy communicated to the anode by the arc. The heat ot the anode isdrawn oi by radiation and conduction, radiation vacting primarilytowards the interior of the container of the rectiiier, while conductionnearly always takes place outwards through the bolt. The latter mode ofheat transmission heats the entire upper portion of the anode. and aboveall the packing of the anodes. The heating of theI anode packing isespecially objectionable for the operation of the rectifier.

The principal object of the invention, therefore, is to retain theinsulator and packing of such anodes in cool state.

Other objects and advantages will hereinafter appear. f

In carrying out the invention, the overheating of the anode packing isreduced as much as possible in the ollowingvmanner. A division isproduced of the heat transmitted from the anode outwards into twostreams in such manner as to oppose a great resistance to the heatstream coming in contact with the anode packing, the heat being at thesamel time transmitted well by radiation and conduction to the air,while for the other stream of heat which does not come in contact withthe packing good thermal conductivity is provided, there being at thesame time good transmission of heat by radiation and conduction to theexterior.

The accompanying drawing shows a crosssectional view of an embodiment ofan anode of this invention. n

l is the head of the anode, Q the anode insulator, 3 the wall of therectifier vessei, 4 the inner packing, 4a the outer packing, the saidinner packing being particularly subject to become overheated. 5 is anouter tube of low thermal conductivity situated against the packing 4,and 6 is an inner tube located within and concentrically with the tube5. The tube 5 is made as thin as possible, and its upper ends is inrelatively good communication with the outside atmosphere by means ofany suitable radiator 8, whereby a great drop of 560,476, and inSwitzerland .Tune 27, 1930.

temperature takes places necessarily along the tube 5, causing theadjacent packing 4 to remain relatively cool. The inner tube 6 consistsof a material providing good thermal conductivity and electricalconductivity. On account of the difference of temperatures between thetubes 5, 6 there results an air current, cool air flowing in from abovethrough the outer circular channel between the two tubes, as shown bythe arrow, and lowing outwardly and upwardly through the inner tube 6and through passageways 7 formed in the latter tube. The said resultingair current is es peciallyeffective for the cooling of the packing 4, asthe latter is swept by the entering cool air, and in the above mannerthe heat of the insulator 2 and the entire anode is transferredoutwardly by the convection of the resulting air current.

Variations may be resorted to within thek scope of the invention, 'andportions of the improvements may be used without others.

Having thus described the invention, I claim l. A vapor anode havingtherefor a cylindrical insulator, a tube of low thermal conductivitylocated within said insulator, a tube of high thermal conductivitylocated within said tube, and leaving an air convecting space betweenthe tubes leading to the exterior atmosphere, and said high conductivitytube having its bore leading to the exterior atmosphere and in its walla passageway joining the inner spaces of both of said tubes.

2. A vapor anode having therefor a cylindrical insulator, a walledstructure within said insulator including an internal chamber connectingwith the exterior atmosphere and a chamber surrounding said formerchamber connecting with the exterior atmosphere, said chambers being inintercommunication, and said structure including material of variousthermal conduotivities to cause through convection a stream of air to bedrawn into said surrounding chamber toward the walls of the insulator`and to be expelled through said internal chamber.

Signed at Zurich, Switzerland, June 23d,

MAX WELLAUER.

